1. Field of the Invention
The present invention pertains to a timepiece such as a wrist watch and a pocket watch, and more particularly to a timepiece comprising an attachable and detachable bezel.
2. Description of the Prior Art
It is preferable to make a bezel attachable and detachable, since upon maintenance a damaged bezel can be replaced not only with a bezel of the same type, but also with a bezel of a different type having a different design which offers a different decorative effect at will.
According to a first example of a conventional wrist watch including an attachable and detachable bezel, an annular protrusion is formed on the outer periphery of an annular step defined on a case band the inner periphery of which a cover glass is attached to. Another annular protrusion formed on the inner periphery of a rotating bezel engages with the protrusion formed on the case band from below (for example, see JP-A-10-239454 (paragraphs 0003 through 0005, paragraphs 0018 through 0028, FIGS. 1 through 5, FIGS. 19 through 23) and JP-A-5-312972(FIGS. 1 and 2)).
According to a second example of a conventional wrist watch, an annular groove is formed on each of oppositely disposed faces of an annular step of case band and a rotating bezel engaging with the step, and a polygonal spring is fitted to the grooves so as to prevent the rotating bevel from slipping off the step (for example, see JP-A-10-239454).
Additionally, according to a third example of a conventional wrist watch, a rotating bezel has an outside bezel and an inside bezel releasably screw-engaging with the outside bezel, and the outside bezel is fixed to an annular step of a case band by means of a polygonal spring so as to avoid the separation of the rotating bezel from the step (for example, see JP-A-10-239454).
In the first example of the related art, the connection between the case band and the bezel is strong. Thus, for separating the bezel from the case band, it is necessary to insert a specialized thin plate tool between the bezel and the case band and force the bezel open by the tool. Accordingly, the bezel is very likely to be damaged by a great operational force given thereto, and such a great force is also required to attach the bezel to the case band.
In the second example of the related art, it is necessary to insert a specialized thin plate tool between the bezel and the case band and force the bezel open by the tool for detaching the bezel from the case band since the polygonal spring cannot be directly deformed. Moreover, the polygonal spring is costly.
In the third example of the related art, for removing the bezel from the case band the inside bezel is first removed from the outside bezel, and subsequently the outside bezel is separated from the case band by deforming the polygonal spring. However, for the attachment and removal of the inside bezel to and from the outside bezel, the inside bezel needs to be rotated by a tool which catches a plurality of concaves of the inside bezel. Thus, a special-purpose tool is still required in this case. Furthermore, an additional specialized tool for the polygonal spring is needed for deforming the polygonal spring apart from the tool for the inside bezel. In addition, the polygonal spring is costly.
As mentioned above, a special-purpose tool is required at least for separating the bezel from the case band in any of the related art examples. Thus, it is difficult for a user to replace the bezel with ease even if a bezel of a different type having a different design can be offered. Accordingly, the attachment and removal of the bezel is done at a watch store or by other specialist, which is inconvenient for a user.
An object to be achieved by the present invention is to provide a timepiece having a bezel which is easily attached and removed by a user without requiring a specialized tool.